Synthesis of naphtho[2,1-b]furo[3,2-e]-1,4-diazepin-2-ones and naphtho[2,1-b]furo[3,2-e]-1,3,4-triazepin-2-ones of pharmacological interest

• Published in: Indian journal of chemistry. Sect. B. Organic chemistry, including medicinal chemistry Vol. 43; no. 7; pp. 1537 - 1543
• Main Authors: Vaidya, VP, Vagdevi, HM, Mahadevan, KM, Shreedhara, CS
• Format: Journal Article
• Language: English
• Published: NEW DELHI Natl Inst Science Communication & Information Resources-Niscair 01.07.2004
• Subjects: Chemistry; Chemistry, Organic; Physical Sciences; Science & Technology; NAPHTHO
• ISSN: 0376-4699; 0019-5103

2-Hydroxy-1-naphthonitrile 1 on treatment with different haloketones affords corresponding 2-acyl-3-amino-naphtho[2,1-b]furans 2a-c. The compounds 2a-c on refluxing with chloroacetyl chloride produce 3-chloroacetamido-2-acylnaphtho[2,1-b]furans 3a-c, which on subsequent treatment with methanolic ammonia yields the desired naphtho[2,1-b]furo[3,2-e]-1,4-diazepin-2-ones 4a-c. The synthesis of another intermediate 3-aminonaphtho[2,1-b]furan-2-carboxylate 5, is accomplished by reacting 1 with ethyl chloroacetate. The compound 5 is converted into 1H-2,3,4,5-tetrahydronaphtho[2,1-b]furo[3,2-e]-1,4-diazepin-2,5-dione 7 via ethyl 3-chloroacetamido naphtho[2,1-b]furan-2-carboxylate 6. The reaction of 2a-c with ethyl chloroformate results in the formation of 2-acyl-3-carbethoxyaminonaphtho[2,1-b]furans 8a-c, which are further converted into different hydrazones 9a-i. The cyclisation of hydrazones 9a-i to 5-alkyl/aryl-3-substituted-1H-2,3-dihydronaphtho[2,1-b] furo[3,2-e]-1,3,4-triazepin-2-ones 10a-i is achieved by refluxing in acetic acid. The structures of newly synthesized compounds have been established by elemental analysis and spectral data. Their antimicrobial, anthelmintic and analgesic activities have been evaluated.